Ultra-violet sensitive layer



PatentedNo 7, 1933 owns-wows llmuel Sheppard New Bio fierl i si This invention relates to plioto sensltive ls. ers, the sensitivity of which lies chiefly the ultra-violet.

it is desirable icr certain octinometric pur= poses to have a. light sensitive material which reacts to the near ultra-violet rays, without being oppreciobly afiected by the rest of the spectrum. Specifically, such 2. paper may be used to demon-- strate or close the ultra-violet radiation of sunlight and of various artificial light sources, per= ticulorly those used tlieropeuticolly. It is an o ject of this invention to produce such paper, although it is understood that these mete- :5 may be coated on other supports and may used s for other purposes.

such as glucose or dextrose, a layer will be oc-.

tamed which will give a visible image in a. short time when exposed to ultra-violet light.

"The general reaction on which this result E loosed may be represented as In this reaction Q represents a metal ion, and 0 oxygen. In these reactions the liberated oxygen is used to oxidize the added substance such as glucose or dextrose.

Specific examples of our invention are the following:

Example I Sodium tungstate I Dextrose 1 10 grams Water 1000 c. c.

Toithis sufflcient hydrochloric acid to make defl- 'nitely acid is added. About 0. 0. of 8- drochloric acid is sufllcient.

This composition may be coated on a paper or other support, or the paper may be floated upon it and then withdrawn and dried.

Another suitable coating composition is ti. 1 designers to @ompeuy, it-collector, ll. o

Mon W. in,

For a. geletine uoting, which is more clesimlile for certain purposes, the following composition is suitable:

- Example HZ Oi the above compositions when cost-ed on paper and exposed to intro-violet light will show a. positive color change from white to iolue. The maximum sensitivity of the tungsten compound has been found to lie in the region oi esoo so strom units while tlmt of molybdenum is neuter L000 Angstrom units. These coatings have very little sensitivity in the visible spectrum beyond 4,000 fingstrom units.

We contemplate as included within our inven tion all variations and equivalents coming within the scope of the appended 019..

What we claim is:

l. A photo-sensitive layer sensitive the ultra-violet comprising an oxygen-containing compound of a metal of the VIth group of the Sodium molylorlnto mggps Dextrose 1c Water o. c.

To which is added Citric sold 20 Sodium tungstete grouse Dextrose l2 Welter 15f? c. Hydrochloric Enid 35% zit o. The acidified t mstcte solution is then ou loo c. c. 10% gelstine. The solution may be coated on photographic popes or other support on known method.

primarily to 99 periodic table having an atomic weight between and 200, and dextrose.

2. An actinometric paper sensitive primarily to 5 the ultra-violet comprising a. support and a coat-'- ing containing sodium molybdate and dextrose.

' 3. An actinometric paper sensitive primarily'to the ultra-violet comprising a. support and a coating containing sodium tungstate and dextrose.

I 4. The method of making a photo-sensitive layer sensitive primarily to the ultra-violet which comprises coating a. suitable support with amlxture containing sodium molybdate and dextrose.

5; The method of making a..photo-sensitive 5' layer'sensltive-primarily to the ultra-violet which comprises coating 2. suitable support with a mix-' ture containing sodium tungstate and dextrose.

. SAMUEL E. SHEPPARD.

LEON woo man, 

